Staining Methods And Aseptic Techniques
INTRODUCTION The microscopic examination of stained preparation. Gives idea of the morphology of bacteria ( cocci, bacilli, spirilla, etc.). Helps to determine the staining affinity of bacteria ( Gram positive, Gram negative, acid fast, etc.). Demonstrates the purity of the culture. Demonstrates the bacteria present in the sample material to be cultured. Helps to diagnose organisms such as gonococci, acid fast bacilli, etc. By direct microscopic ex- amination. Staining requirements Stains: They can be basic, acidic or neutrals salts. Most of the stains that are used to stain bacteria are of the basic type. The nucleic acid of bacterial cells attracts the positive ions of basic stains. Ex- Basic fusion, methylene blue, crystal violet, etc. Acidic stain are mainly used in microbiology to provide background staining. Example - Eosin. Neutral stains are used to stain nucleic acid and cytoplasm. Example - Giemsa stain. The majority of stains used in microbiology are o...